1. Field of the Invention
The present invention relates to a constant level oiler wherein a means for venting is provided which eliminates the need for the large surge chambers inherent in the prior art devices.
2. Description of the Prior Art
Devices known as constant level oilers are employed to provide a steady flow of lubricant from a reservoir containing a lubricating fluid to a piece of operating machinery. Such oilers generally comprise upper and lower cylindrical reservoirs. The upper reservoir effectively stores the lubricating fluid while the lower reservoir supplies the lubricating fluid at a constant level to the machine needing lubrication and acts as a surge chamber when the machine under lubrication is switched off.
In the devices of the prior art, a cover having an aperture in the center thereof to accommodate a filler plug is used to effectively form an air tight seal in the upper portion of the upper reservoir. Separating the upper reservoir and surge chamber is a dividing section having an aperture through the center thereof. A hollow tubular body located about the perimeter of the aperture extends partially into the open region of the surge chamber. In the upper region of the surge chamber, there is a vent aperture which allows venting of a supply of air therethrough. An outlet aperture located in the lower region of the surge chamber is used to allow the lubricating fluid to flow therethrough to the machine needing lubrication.
The prior art oiler also comprises a rod which extends axially through the center of the upper cylinder and which terminates in a valve member that extends into central region of the hollow tubular body in the surge chamber. The rod is upwardly biased by a spring thereby causing the valve member to seal the aperture of the dividing section when the plug is removed during filling. When the plug is secured to the aperture in the top cover, the rod is driven against the bias of the spring thereby opening the aperture in the dividing section and allowing the lubricating fluid stored in the upper reservoir to flow into the surge chamber and therefrom to machine under lubrication. As the fluid enters the surge chamber, the air contained therein is displaced through the vent aperture until the fluid reaches the level defined by the lower portion of the hollow tubular body. Upon reaching such level, the fluid flow from the upper reservoir ceases. It is at this level that the fluid in both the surge chamber and the machine under lubrication is maintained.
As the machine under lubrication uses the fluid, the level of the fluid in the surge chamber is reduced to a level below the constant level defined by the lower portion of the hollow tubular section. As such, air is allowed to flow through the hollow tubular body and into the upper reservoir thereby causing the lubricating fluid to flow downward into the surge chamber to replenish the fluid used and thus maintain the fluid in the surge chamber and machine at a constant level.
Great quantities of the lubricating fluid may be needed to establish an operating fluid level since such fluids generally adhere to the portions of the machine which are in motion. Consequently, when the machine under lubrication is shut down, a new level of fluid is established above the running level thereby causing the fluid to surge back into the surge chamber. As such, the surge chamber must have a fluid capacity which is sufficiently large enough to accommodate the surge without allowing the fluid to overflow from the vent aperture. The need for such a large surge chamber increases the cost of the oiler and proves to be a burden in applications having limited space availability.
It is an object of the present invention to provide a constant level oiler wherein the need for a large surge chamber is eliminated thereby providing cost and space savings over the constant level oilers of the prior art.
It is a further object of the present invention to specify a constant level oiler wherein the attendant ill-affects of lubricating fluid overflow caused by machine shutdown are eliminated.